Understanding the A518 Transmission
Overview of the A518
The rumble of the engine, the satisfying shift of gears – there’s a certain joy that comes with driving a well-maintained vehicle. But what happens when those smooth shifts turn into harsh jolts, when power feels sluggish, or when ominous leaks begin to appear? Often, the culprit is the transmission, and for owners of classic Dodge trucks, vans, and many other vehicles from the era, the A518 transmission is a familiar component. When problems arise, a reliable A518 transmission rebuild kit is often the key to restoring your vehicle’s performance. This guide will walk you through everything you need to know about choosing and using a A518 transmission rebuild kit to get your vehicle back on the road.
The A518, also known as the 46RH, is a four-speed automatic transmission that found its home in a wide range of vehicles, particularly in the Chrysler family. Its design is robust, built to handle the demands of work trucks, vans, and a variety of car models. Understanding its basic mechanics is the first step towards successful rebuilding. The transmission relies on a series of clutch packs, bands, and a complex valve body system to smoothly change gears. The heart of the A518 is its internal mechanics, composed of friction plates, steel plates, seals, gaskets, and other precisely engineered components working in concert.
Over time, like any mechanical marvel, the A518 is susceptible to wear and tear. Heat, friction, and the simple passage of time can take their toll on its internal workings. This can manifest in several ways, and recognizing these signs is crucial for early intervention.
Common Symptoms of A518 Transmission Problems
One of the most noticeable signs of a failing A518 is slipping gears. This occurs when the transmission fails to properly engage the intended gear, resulting in a loss of power or the engine revving without a corresponding increase in speed. Delayed engagement, where the transmission hesitates before shifting, can also point to internal issues, often related to worn clutch packs or faulty seals.
Harsh shifting, characterized by jarring shifts between gears, is another common symptom. This can be caused by a variety of problems, from worn bands to a malfunctioning valve body. Transmission fluid leaks, often appearing as red or pinkish puddles beneath the vehicle, are a clear sign that seals and gaskets are failing, leading to a loss of fluid and potential damage.
Unusual noises, such as whining, clunking, or grinding, can also signal trouble. These sounds may indicate worn gears, failing bearings, or other mechanical problems. Each of these symptoms, when taken together, are strong indicators of the need for inspection and possible service.
Considering these symptoms, you’re now equipped to determine if your A518 transmission rebuild kit needs will become reality.
Why Rebuilding is a Good Option
When faced with A518 transmission problems, there are several options: complete replacement, a used transmission, or rebuilding the existing unit. While replacing the transmission might seem like the easiest solution, it can be considerably more expensive. Finding a used transmission carries the risk of inheriting someone else’s problems. Rebuilding, on the other hand, offers several compelling advantages.
First and foremost, rebuilding is often the most cost-effective approach. It allows you to repair the transmission rather than replacing it, saving a significant amount of money. Second, rebuilding provides an opportunity to upgrade components. Performance-oriented rebuild kits include upgraded clutch plates, strengthened bands, and other enhancements to improve the transmission’s durability and performance. This makes the transmission perform better than it would if left original.
Finally, rebuilding the transmission allows you to preserve your vehicle’s originality, especially if you own a classic or vintage vehicle. If you’re committed to maintaining your vehicle’s original character, repairing and rebuilding the existing transmission is the best path.
Components of an A518 Transmission Rebuild Kit
The success of any A518 transmission rebuild depends on the quality of the components used. A A518 transmission rebuild kit contains the parts necessary to restore the transmission to its original condition.
Friction Plates and Steel Plates
Friction plates and steel plates are critical components of the clutch packs. The friction plates, as the name implies, are designed to create friction, allowing the transmission to transfer power between the engine and the wheels. Steel plates provide support and distribute pressure. The friction and steel plates within the clutches and bands see extensive wear and tear. High-quality friction plates are crucial for ensuring smooth and reliable shifting. A worn friction plate can cause slipping gears.
Seals and Gaskets
Seals and gaskets are another crucial element. Their main function is to prevent leaks and maintain proper fluid pressure within the transmission. The seals and gaskets of the A518 are made of rubber compounds and undergo extensive heat and pressure. The A518 transmission rebuild kit will include a variety of seals and gaskets designed to fit specific locations throughout the transmission.
O-Rings
O-rings are small but incredibly important, providing a tight seal in various locations within the transmission. These are often overlooked but are crucial for preventing leaks and maintaining proper fluid pressure. The kit will also offer the option to replace the O-rings as well.
Band and Clutch Considerations
The band and clutch packs are responsible for engaging and disengaging the gears. Over time, the band can wear down, leading to shifting problems. Clutch packs can also wear, resulting in slipping gears and a loss of power. A A518 transmission rebuild kit will often include a replacement band and clutch packs. Correct band adjustment is essential for proper shifting.
Filters
The filter is a vital component for keeping the transmission fluid clean. As the transmission operates, small particles of metal and other debris are generated. These can contaminate the fluid and damage the internal components. A A518 transmission rebuild kit will include a new filter.
Other Components
Depending on the specific kit, it may include a variety of other components such as bushings, thrust washers, and other parts that help to maintain the transmission’s efficiency. These components contribute to the overall performance and longevity of the transmission.
Choosing the Right A518 Transmission Rebuild Kit
Selecting the correct kit is crucial for a successful rebuild. Knowing what’s available and which kit is right for your car is essential.
Types of Kits
Basic Rebuild Kits are the most fundamental, including the essential components needed to address common problems, like seals, gaskets, and friction plates. These are a good starting point for addressing leaks and minor issues.
Master Kits build upon basic kits, adding more components, such as bands, and sometimes, additional friction plates and steel plates. These kits are suitable for more comprehensive rebuilds, addressing more extensive wear and tear.
Performance Kits take things a step further by including high-performance components designed for increased power-handling capabilities. These kits are designed for vehicles that are modified or used in demanding applications.
Identifying Your Specific Model
The A518 transmission was produced in a variety of configurations. Before purchasing a kit, it’s vital to identify your exact transmission model. You can usually find this information on a tag attached to the transmission itself, or by checking the vehicle’s build sheet or service manuals. Matching the rebuild kit to your specific model ensures proper fitment and functionality.
Brands and Kit Quality
The market is filled with different brands, but not all are created equal. Look for brands known for quality, reliability, and customer support. Researching specific brands is a must. Reading customer reviews, checking for warranties, and comparing the materials used in the kit can help you make an informed decision. Investing in a reputable brand is key.
Where to Buy
A A518 transmission rebuild kit can be purchased from various sources, including online retailers, automotive parts stores, and specialized transmission shops. Research the vendor’s reputation, compare prices, and consider shipping options before making your purchase.
The Rebuilding Process (High-Level Overview)
Rebuilding an A518 transmission is a complex task that requires patience, precision, and the right tools. This section provides a general overview of the process.
Preparation
Before starting, gather all necessary tools, including a torque wrench, snap ring pliers, and any special tools specific to the A518 transmission. Prepare a clean and well-lit workspace. Consider having a repair manual on hand for detailed instructions and torque specifications. Also, it is recommended to photograph each step of the process, and to label the components as you disassemble the transmission.
Disassembly
Careful disassembly is critical. Following the repair manual’s instructions is extremely valuable. Remove components in a systematic manner, paying close attention to the order in which they are removed. Take plenty of pictures during disassembly and label each part as it is removed, making reassembly easier and reducing the risk of errors.
Cleaning and Inspection
After disassembly, thoroughly clean all components. Use a parts cleaner to remove all traces of old fluid, debris, and contaminants. Then, inspect each part for wear, damage, or other issues. Examine the friction plates, steel plates, bands, and other components to make sure they are not damaged.
Component Replacement
Replace all the components from your A518 transmission rebuild kit. Follow the repair manual’s instructions for the correct installation and torque specifications.
Reassembly
The reassembly phase is where your notes and pictures from disassembly prove most valuable. Follow the reverse order of disassembly, carefully installing each component. Pay special attention to clutch pack clearances, band adjustments, and valve body installation. Using proper torque during the reassembly process is crucial.
Installation and Testing
Once the transmission is reassembled, reinstall it into the vehicle. Fill the transmission with the correct type and amount of fluid. Start the engine and check for leaks. Test drive the vehicle, paying attention to shifting performance and any unusual noises.
Tips and Considerations
Rebuilding an A518 transmission can be challenging, but by following a few tips, you can improve your chances of success.
Tools and Equipment
A well-equipped workshop is vital for a successful rebuild. Essential tools include a torque wrench, snap ring pliers, seal drivers, and a parts cleaner. Specialized tools might be required, depending on the specific tasks.
Seeking Professional Help
If you’re unsure about any aspect of the process, or if you lack the necessary tools or experience, don’t hesitate to seek professional assistance. An experienced transmission technician can provide valuable guidance and ensure the job is done correctly.
Understanding Torque Specs
Correct torque specifications are critical for proper assembly. Follow the manufacturer’s recommendations for tightening bolts and fasteners. Over-tightening or under-tightening can lead to leaks, damage, or premature failure.
Transmission Fluid and Filter
Use the correct type of transmission fluid recommended for your A518 transmission. Make sure to replace the filter during the rebuild to remove any contaminants from the system.
Preventative Maintenance
Once the rebuild is complete, practice preventative maintenance. Change the transmission fluid and filter at regular intervals and monitor the transmission for any signs of trouble.
In conclusion, a A518 transmission rebuild kit can offer a cost-effective and rewarding way to restore the performance of your vehicle. By understanding the basics of the transmission, choosing the right kit, and following the process with care, you can significantly extend the life of your A518.
Conclusion
Successfully rebuilding an A518 transmission can breathe new life into a vehicle. By choosing the correct A518 transmission rebuild kit, approaching the project with patience, and carefully following instructions, you can restore performance and extend the life of the transmission.
This guide should equip you with the knowledge needed to start this project. For further information, search for videos and forums. Good luck with your rebuild!